Core and Peripheral Voters: Predictors of Turnout Across Three Types of Elections

766246PCX0010.1177/0032321718766246Political StudiesBhatti et al. research-article2018 Article Core and Peripheral Voters: Predictors of Turnout Across Three Types of Elections Political Studies 1 19 The Author(s) 2018 Reprints and permissions: sagepub.co.uk/journalspermissions.nav https://doi.org/10.1177/0032321718766246 DOI: journals.sagepub.com/home/psx Yosef Bhatti 1, Jens Olav Dahlgaard 2, Jonas Hedegaard Hansen 3 and Kasper M Hansen 3 Abstract Citizens who abstain from voting in consecutive elections and inequality in turnout in democratic elections constitute a challenge to the legitimacy of democracy. Applying the law of dispersion, which stipulates higher levels of turnout and higher levels of equality in turnout are positively related, we study turnout patterns across different types of elections in Denmark, a high-turnout European context. Across three different elections with turnout rates from 56.3% to 85.9%, we use a rich, nationwide panel dataset of 2.1 million citizens with validated turnout and high-quality sociodemographic variables. A total of 9% of the citizens are abstainers in the three consecutive elections, and these are disproportionately male, of non-western ethnic background, with little education, and with low income. The law of dispersion finds support as inequalities in turnout increase when turnout decreases and vice versa. Furthermore, municipalities with lower turnout have higher inequalities in participation than high-turnout municipalities in local elections. Keywords voter turnout, participation, law of dispersion, inequality Accepted: 1 March 2018 When the projected turnout for the European Parliament election in 2014 was announced to be 43.1%, a small increase from 43% in 2009, the liberal leader Guy Verhofstadt said, The European Parliament will be more representative than the previous one (Euractiv, 2014). While the final vote count showed that turnout was, in fact, 42.6%, a small decline from 2009, Mr Verhofstadt s focus on representativeness is in line with concerns expressed by many European leaders. Not only political leaders have this focus. Indeed, studying 1 VIVE The Danish Center for Social Science Research, Copenhagen, Denmark 2 Department of Business and Politics, Copenhagen Business School, Frederiksberg, Denmark 3 Department of Political Science, University of Copenhagen, Copenhagen, Denmark Corresponding author: Kasper M Hansen, University of Copenhagen, Øster Farimagsgade 5, 1353 Copenhagen, Denmark. Email: kmh@ifs.ku.dk

2 Political Studies 00(0) inequalities in political participation, and particularly voter turnout, remains a central topic in political science. Participatory equality is often mentioned as a core democratic ideal (Lijphart, 1997; Wolfinger and Rosenstone, 1980). If some groups disproportionately abstain from voting, it may have important consequences for democracy. These groups will have less influence on who is elected and become underrepresented by legislators (Griffin and Newman, 2005; Leighley and Nagler, 2013; Martin, 2003) and, as a consequence, they might identify less with their representatives and mistrust them more (Mansbridge, 1999). Aggregate turnout varies substantially across different types of elections. European countries experience higher turnout rates in national elections than in local and European elections (Blais, 2000: 37; International Institute for Democracy and Electoral Assistance (IDEA), 2016; Morlan, 1984; Reif and Schmitt, 1980). Strong variation across elections is not unique to Europe. In the United States, turnout surges for presidential elections and declines when midterm elections take place (Campbell, 1987; McDonald, 2016). While turnout studies often examine differences between voters and abstainers in individual elections (e.g. Sigelman et al., 1985: 749), only little empirical attention has been given to the variation in the predictors of voting across elections (e.g. Nawara, 2016; Persson et al., 2013). Do the same sociodemographic factors explain the variation in turnout when turnout is 43% as when turnout is 65% (i.e. the national election turnout average among European Union (EU) member states in 2014; IDEA, 2016) and with the same strength? We use validated turnout and register data for more than 2 million citizens who were all eligible to vote in three Danish elections at, respectively, the local, European, and national levels from 2013 to 2015. In the three elections, turnout ranged from 56.3% to 85.9%. The turnout data from the elections are merged with administrative data at the individual level, which contains hundreds of highly reliable sociodemographic variables. This allows us to analyze the predictors of cumulative voting, the total number of votes cast in a number of consecutive elections, in a high-turnout context and the potential differential drop-off of voters across different types of elections. As we rely on a large administrative, individual-level dataset with validated turnout and reliable covariates in different types of elections, we overcome well-known problems of self-reported voting and small survey samples which have characterized much of the previous literature (Bernstein et al., 2001; Dahlgaard et al., 2018; Karp and Brockington, 2005; Smets and Van Ham, 2013). Studies that examine multiple elections often look at cumulative turnout based on citizens history of voting in one type of election (Ansolabehere and Schaffner, 2016; Campbell, 1960; Sciarini et al., 2015; Sigelman et al., 1985; Sigelman and Jewell, 1986). In the first part of our analysis, we look at cumulative turnout across three consecutive elections and thus move beyond the vote/not vote variable in a single election. Consequently, we will learn about those who selectively vote in some elections and not in others. We also learn about the abstainers who seem permanently disconnected from the elections under investigation. To understand these inequalities in turnout further, we apply the law of dispersion, which states that higher general levels of turnout come with higher levels of equality in political participation (Lijphart, 1997; Tingsten, 1937). We take the analysis one step further and investigate explicitly the variation in turnout inequalities across different types of elections. Despite the prominence of the law of dispersion, only few studies have empirically investigated it, and recent empirical contributions show mixed results as Persson et al. (2013) find overall support for the law of dispersion, while Sinnott and Achen (2008) find no support regarding social class and the law of dispersion. Across the

Bhatti et al. 3 three types of elections, we explore whether the difference in turnout between different sociodemographic groups increases when fewer turn out to vote. We find substantial inequalities in cumulative turnout. Across the three elections, 9.3% of the voters, the abstainers, failed to cast even a single vote while 51.2% of the voters, the core voters, voted in all three elections. Notably, the European elections were almost only for the core voters. Only 6.4% of the voters cast a vote in the European election but failed to do so in at least one of the other elections. Core voters and abstainers are far from representative of the voters. Core voters are more likely to be female, better educated, and earn higher incomes. They also tend to be older than abstainers, and they are less likely to have a native background. Together, these findings show that the law of dispersion also applies when studying cumulative participation. We also find evidence supporting the law of dispersion when comparing the individual elections. In low turnout elections, it is especially voters with no or little education who drop off. The differences in turnout across ethnicity also increase as voters of Western background are less behind ethnic Danes in local elections compared to national elections. Finally, we show that the turnout gap regarding education and ethnic background is negatively correlated with turnout in local elections across Danish municipalities. This indicates that inequalities follow the aggregate level of turnout, as predicted by the law of dispersion and not just the type of election under investigation. Studying Inequalities in Turnout and the Law of Dispersion Inequalities in voter participation have been on political scientists agenda for decades. Scholars concerned with the well-being of representative democracy argue that large inequalities in turnout might pose a legitimacy problem for representative democracy as the opinions of the elected politicians become too much out of sync with the attitudes of the citizens (cf. Tingsten, 1937: 184). Furthermore, it is questionable whether the core idea of elections to elect representatives for the people can be said to be meaningfully met if inequalities in participation are too large (Lijphart, 1997; Wolfinger and Rosenstone, 1980). With such concerns in mind, empirical research has focused on determining who votes as well as what predicts and causes citizens turnout decision. Of particular relevance regarding inequalities in turnout is the degree to which some sociodemographic characteristics, such as ethnicity, age, gender, and education, predict turnout (Bhatti et al., 2016c). In the existing literature, a substantial amount of research has investigated questions like this in single elections or the same type of elections over time in a given country. In a meta-analysis of 95 published turnout studies from 2000 to 2010, Smets and Van Ham (2013) show that education, age, residential mobility, region, and turnout history consistently correlate with turnout at the national level. However, gender, ethnicity, employment, and citizenship correlate with turnout in some settings but not consistently across studies (Smets and Van Ham, 2013). While these findings are, indeed, useful, there are limitations. First, only 11% of the reported studies use validated turnout as the dependent measure (Smets and Van Ham, 2013: 346). This leaves them vulnerable to well-known problems of overreporting of selfreported turnout (Bernstein et al., 2001; Dahlgaard et al., 2018; Karp and Brockington, 2005). Furthermore, most studies also use self-reported independent variables such as income and educational attainment, which can also be misreported (Hariri and Lassen, 2017). This makes the actual relationship between turnout and sociodemographic

4 Political Studies 00(0) characteristics even more uncertain. Second, and related, studies using validated turnout in a European context are very rare (cf. Smets and Van Ham, 2013). 1 Third, some factors are likely to be relevant in some contexts and not in others. Indeed, Smets and Van Ham (2013) restrict their sample to include only national elections based on the argument that some independent variables might affect turnout differently in first-order elections compared to second-order elections (Smets and Van Ham, 2013: 345; see also Fieldhouse et al., 2007). Therefore, we still lack knowledge about how different variables correlate with turnout across different types of elections but for the same individuals, which is at the core of the law of dispersion. This article s first contribution is to fill this knowledge gap by investigating the characteristics of core and peripheral voters as well as the abstainers across elections. 2 Specifically, we ask to what degree inequalities in participation exists across elections. By studying cumulative turnout, we shift the focus from the one-election, voted/abstained variable used in single-election studies to participation in multiple consecutive elections. We define cumulative voting as the number of votes cast in three consecutive election. We can think of the electorate as being made up of a core that votes consistently in any election, a periphery that votes occasionally, and a group of abstainers who do not participate in elections (Ansolabehere and Schaffner, 2016; Sciarini et al., 2015). The peripheral voters are less intrinsically interested in politics and know less about politics compared to the core voters (Nawara, 2016), and it requires more short-term stimulation such as dramatic issues or events, popular candidates on the ticket, or extensive campaigning to motivate the peripheral voters to participate in the election. The core voters, however, have sufficiently high levels of political interest to vote in elections, even when the level of political stimulation is relatively weak (Campbell, 1960; Fieldhouse et al., 2007). The abstainers are the ones who fail to vote in three consecutive elections. They might simply be politically disengaged or have opted out of the political process. We are interested in measuring the proportion of the core and peripheral voters as well as the abstainers. On one hand, if it is different citizens who abstain from election to election, we might be less concerned with the democratic legitimacy of the election as voters will in this sense accept the social contract of the election sooner or later. On the other hand, we might be more concerned about the health of representative democracy if it is the same citizens who repeatedly abstain from voting (Sciarini et al., 2015). For instance, research from Geneva, Switzerland, suggests that approximately 20% abstain from voting in 10 successive direct votes (Sciarini et al., 2015). In the United States, around 37% failed to vote in four national elections (two midterms and two presidential) from 2006 to 2012, whereas 25% voted in all four elections (Ansolabehere and Schaffner, 2016). How the levels are in the context of our study, a European country with a high-turnout rate, is descriptively an important question. This article s second contribution is to apply the logic of the law of dispersion in an analysis of cumulative participation. The law of dispersion refers to the idea that inequalities in turnout increases when aggregate turnout declines (Lijphart, 1997; Persson et al., 2013; Rosenstone and Hansen, 1993; Tingsten, 1937). In this way, lower turnout equals larger inequalities in descriptive representation. 3 While the scholarly focus primarily has been on comparing turnout inequalities in different types of elections, we extend the logic of the law of dispersion to an analysis of turnout inequalities across multiple elections of the same type. We do this by investigating the sociodemographic characteristics of the different groups introduced above across almost 100 municipal elections held simultaneously.

Bhatti et al. 5 It is especially important to investigate the characteristics of the abstainers, those disconnected from the electoral process. Furthermore, knowledge about the social profile of the groups can tell us whether the peripheral voters look mostly like the core voters or the abstainers. In the Swiss study, peripheral voters share most characteristics with the abstainers (Sciarini et al., 2015). In both the American and Swiss studies, older voters are more likely to be core voters (Ansolabehere and Schaffner, 2016; Sciarini et al., 2015). Additionally, ethnic minorities are less likely to be consistent voters in the US context. In this article, we explore whether core and peripheral voters are also descriptively different in a high-turnout context. Compared with the previous studies, our article has the additional advantage of access to a rich set of sociodemographic variables none of which is self-reported. In addition to the variables discussed above, we expect that citizens with higher levels of education are less likely to be abstainers; a pattern which has previously been documented in Denmark and single-election studies in many other countries (cf. Bhatti et al., 2016a; Bhatti and Hansen, 2012; Persson, 2015; Smets and Van Ham, 2013). This article s third contribution is an analysis of the law of dispersion in the traditional way by analyzing the sociodemographic patterns in turnout in different types of elections. If some voter groups are more likely to drop off from the electorate than others in certain elections, we could see descriptive differences between the general electorate and those who exercise their right to vote. Perhaps, differences in drop-off rates are nonmonotonic, and some groups initially see the largest drop-off rates, while other groups catch up in terms of drop-off if turnout falls even lower. In that case, we could imagine turnout to be descriptively more equal when turnout is, say, 50% instead of 70%. Consequentially, whether differential levels of turnout increase or decrease differences across groups, voter participation depends on what type of voters drop out of the electorate when turnout declines and at what point (Sinnott and Achen, 2008). Furthermore, we could imagine different types of voters to drop off in different types of elections. For instance, we might imagine that highly educated, young citizens are likely to follow European politics more intensively and thereby be more likely to vote in low-salience European elections than young citizens with less education. At the same time, this group might be less invested in local government issues and thus be the first to drop off in local elections. Thus, we can imagine the aggregate turnout being the same in two different types of elections but with widely different turnout across groups since different kinds of voters are less attracted to different kinds of elections. Whether this is the case is an empirical question, which we analyze in this article and thereby contribute with an analysis of the law of dispersion in a high-turnout context in three types of elections. Data and Context: Three Danish Elections From 2013 to 2015 We use data from three Danish elections from 2013 to 2015, specifically the Danish municipality elections held in November 2013, the European elections in May 2014, and the parliamentary election held in June 2015. While Denmark has a high turnout compared to most other European countries, we note that the participation ratio between the national election and European parliamentary election in Denmark is around 3:2, which is similar to the participation ratio across 27 EU countries. 4 Thus, even though turnout in Denmark is generally high, the relative differences in participation between elections are similar, which arguably makes the analysis even more useful for understanding turnout dynamics in other European countries.

6 Political Studies 00(0) In Denmark, there is substantial variation when it comes to the saliency of the elections and the average participation levels over time. In Table 1, we display turnout rates in the most recent of each type of election. National elections are called by the prime minister under the restriction that the election must be held within 4 years of the latest election. To vote, one must be at least 18 years old on Election Day, have Danish citizenship, be a permanent resident in the realm, and not be under guardianship. The national elections involve extensive campaigning and wall-to-wall coverage in most media outlets. The average turnout from 1970 to 2015 has been 86.3%. In other words, the Danish national elections are highly salient. Local elections take place simultaneously in November every 4 years across all 98 Danish municipalities. The turnout has averaged approximately 70% over the last 40 years. Eligible to vote are those who can vote in the national elections, EU citizens and citizens from Norway and Iceland with a permanent residence in Denmark, and non-eu citizen with at least three consecutive years of permanent residency in the country before the election. They also must be 18 years of age and not be under guardianship. Consequentially, the number of eligible citizens is higher for local elections (cf. Table 1). The municipalities play a key role in providing welfare services and decide on tax levels with some degree of autonomy. While they are less salient than national elections, the local elections are still highly visible in the streets and media in the period running up to the election, and they are relatively high salient in a comparative perspective. European elections draw the least attention of the three types of elections and are in a Danish context perceived as second-order elections (cf. Reif and Schmitt, 1980; Schmitt, 2005). There is less campaigning, and the media attention is less intense and of a shorter duration. The turnout has averaged around 50%, which still places the Danish turnout levels among the highest in the EU countries without compulsory voting. Overall, the European elections in Denmark can be categorized as a low-to-medium salient event. In the European elections, voters from EU countries who are 18 years of age and permanent residents in the country can vote if they are not under guardianship. All three elections follow proportional representational principles. All eligible voters are automatically registered to vote and receive a voting card approximately 10 days before the elections, and the logistic barriers for voting are quite low. 5 In our study, we use validated turnout that stems from the official voter lists. In Denmark, voter lists are usually destroyed shortly after the election. However, in 2013, 2014, and 2015, we received permission to collect the lists, and all municipalities were encouraged to send the lists in digital form to us. In case the lists were not digitized, the municipalities had to do this before delivering them to us. In 2013, all municipalities delivered the information, 61 municipalities delivered in 2014, and 72 municipalities in 2015. Thus, we have an almost complete dataset for the 2013 election but somewhat incomplete datasets for the rest of the elections. The lack of turnout data is due mostly to some polling stations using manual voter lists and the municipalities not having resources to digitize the lists in all elections. Early voters are also validated and correctly classified as having cast a vote. It is important to highlight that there was little room for self-selection in the study at the individual level. If voters were assigned a polling station that delivered turnout information to our research team, their turnout data would go into the study without further ado. However, when studying cumulative voting, we use only voters with complete voter records. As an implication, there will be voters who are excluded based on their moving patterns if they have moved from one municipality with recorded turnout in one election to one without turnout in another election. Similarly, some voters have had a moving

Bhatti et al. 7 Table 1. Descriptive Overview of the Elections. Local European National 2013 2014 2015 Actual turnout (%) 71.9 56.3 85.9 Eligible citizens (N) 4,409,251 4,141,329 4,145,105 N in our sample 4,362,156 2,339,064 3,097,536 Turnout in our sample (%) 71.9 56.5 85.8 Turnout for panel part of sample (%, N = 2,093,796) 74.8 57.5 86.3 pattern where had they not moved they would have been excluded because they had stayed in a municipality without recorded voter turnout. Compared to alternative ways of tracking voters, these are very limited attrition problems. Survey investigations of multiple elections potentially suffer from the challenge of differential self-selection depending on the type of elections which makes the results from the various elections incomparable. In sum, even though the turnout data are incomplete, a large panel dataset without individual-level self-selection or self-reporting of either voting or any covariates is a leap forward for the turnout literature, and it is particularly important for empirical analysis of the law of dispersion. In our analysis, we focus on the panel part of the dataset. Consequentially, citizens who were not eligible to vote in one of the elections are removed from the dataset. In practice, this means that the minimum age in the dataset is approximately 19 years and 7 months. Furthermore, due to the difference in eligibility, a group of non-danish citizens who can vote in local elections, but not in national or European elections, are removed from the analysis. Since non-danish citizens and young people turn out at quite low rates, removing them also explains why, in Table 1, we see that turnout in the panel part is approximately 3 percentage points higher than the actual turnout in the local and the European elections. We also remove individuals who in at least one election lived in a district that did not supply turnout information to the study. Finally, we remove citizens for whom we lack information about one of the independent variables that we are applying in the analysis (38,086 observations). Altogether, the dataset covers unique individual-level register data on turnout and hundreds of sociodemographic variables for 2,093,796 citizens across the three elections. The turnout data are merged with administrative data from Statistics Denmark. 6 All Danes have a unique civil registration number which in an anonymized form is used to link a wide range of variables from administrative records maintained by Statistics Denmark. The data include variables that are often used in turnout studies, such as education, age, gender, marital status, ethnicity, and so forth. Since they are administratively collected, they are full population records without individual self-reporting. Our unique data quality further strengthens the empirical contribution to the understanding of individual-level turnout behavior in a European, relatively high-turnout context. Analysis Cumulative Turnout and Inequality Table 2 presents an overview of the cumulative turnout across the three elections.

8 Political Studies 00(0) Table 2. Voting Patterns in Three Elections. Voter type Local European National Percentage N 2013 2014 2015 Abstainers Did not vote Did not vote Did not vote 9.3 194,484 Peripheral Voted Did not vote Did not vote 2.7 55,528 (1/3 votes) Did not vote Voted Did not vote 0.6 12,168 Did not vote Did not vote Voted 10.8 226,112 Peripheral Voted Voted Did not vote 1.2 25,197 (2/3 votes) Voted Did not vote Voted 19.7 413,445 Did not vote Voted Voted 4.6 95,567 Core Voted Voted Voted 51.2 1,071,295 Total 100 2,093,796 Table 2 reveals considerable variation in turnout patterns. We see that 9.3% failed to vote in all three elections (row 1 in Table 2), thereby being categorized as abstainers. At the other end, 51.2% voted in all three elections. These are categorized as core voters. This leaves around 40%, the peripheral voters, who vote in some, but not all, elections. Within this group, there is some noteworthy variation. For instance, approximately 14% voted in one election (rows 2 4 in Table 2), and most of these participated in the national election. Similarly, 25.5% voted in two elections (rows 5 7 in Table 2), again in most cases with one of the elections being the national election. The European elections are also revealed to be the least appealing in Table 2. Only 5.8% voted in the European elections but failed to do so in one of the other elections, and just 0.6% voted in that election alone. Combined, only 6.4% of the voters participated in the European election without participating in at least one of the other elections. Finally, only 1.8% voted in the European elections without voting in the national elections. In other words, it is almost exclusively core voters who bother to vote in the European elections, and almost no one votes exclusively in those elections. Next, we look at the characteristics of the groups. In Table 3, we present some descriptive demographics for the abstainers, the peripheral voters, and the core voters to highlight any inequalities in turnout across groups. We see substantial differences in the sociodemographic composition of the three groups. Non-Western voters comprise 12.4% of abstainers compared to 3.8% of all voters and only 1.3% of core voters. Even though there are more than five times as many core voters than abstainers, voters with a non- Western background are still more likely to be abstainers than core voters. This pertains even though only individuals with Danish citizenship are eligible to vote in national elections, meaning the group with a non-western background in this table is all citizens and have been permanent residents of the country for many years. There is also a substantial educational gap between the groups. Citizens with a higher education make up 39% of the core voters and only 11% of the abstainers. Furthermore, there is a large gap in terms of income with core voters earning 52% more than abstainers. We also see a higher share of women in the core group than in the abstainer group. In Table A1 in Appendix 1, we show three regression analyses with cumulative participation as the dependent variable and the variables in Table 3 as independent variables alongside with other control variables and municipality fixed effects. These analyses are

Bhatti et al. 9 Table 3. Demographic Characteristics of Abstainers, Peripheral, and Core Voters. Female (share, %) Age (mean, years) Non-Western background (share, %) Higher education (share, %) Yearly income (DKK) N Abstainer (0/3) 46.6 47.5 12.4 11.1 236,215 194,484 Peripheral (1/3) 49.7 44.5 7.4 19.4 284,654 293,808 Peripheral (2/3) 52.2 48.0 3.7 26.9 319,618 534,209 Core voter (3/3) 52.1 53.2 1.3 39.4 359,131 1,071,295 Mean 51.3 50.1 3.8 30.8 327,182 2,093,796 All demographic information is from the time of the 2015 election. Non-Western background refers to immigrants and descendants from non-western countries, a category defined by Statistics Denmark. 7 Higher education consists of citizens who have completed either a higher education (e.g. school teachers) or a college education. The large sample size implies that even very small differences are statistically significant. in line with the results in Table 3 and confirm most of the predictions. Although we in no way claim causal relationships, we can conclude that over three elections, gender, age, income, ethnicity, and educational attainment are strong indicators of voting. We think that this an important descriptive finding also in the light of increased immigration to Western Europe in the recent years and the possible consequence for future turnout. The Predictors of Turnout in Different Types of Elections So far, we have shown that sociodemographic variables predict cumulative voting. A related question is whether the law of dispersion applies. To investigate this, we now turn to studying each of the elections independently. Below, we compare how different sociodemographic variables predict turnout across our three types of elections. Are the predictors stronger in elections with lower turnout as the law would suggest? We conduct three regression analyses using the same covariates. For each regression, we switch the dependent variable to be turnout in each of our election years in turn. That way, we learn how strong predictors each of our variables of interest are of turnout in each of the elections. For each of the elections, we conduct a regression analysis including the same variables as in the analysis of cumulative participation including municipality-level fixed effects. We present the average marginal differences for our variables of interest based on Figure 1 and show the complete models in Appendix 1. Figure 1 shows that the turnout gap tends to be smallest in the high-turnout national elections for all groups except for the gender differences, where the gap is nonexistent in the European elections, and for differences between voters with a non-western background and the two other groups. Compared to ethnic Danes, the difference is practically the same in local and national elections. Compared to voters with a Western background, the difference is smaller in local elections than in the national election. Especially in the European elections and with respect to education, in general, the law of dispersion holds firm: In the elections with the lowest turnout rates, the differences between subgroups of the electorate are large. The picture is particularly interesting for two groups. First, the ethnic groups participation differs a lot, and ethnic Danes participate much more than immigrants and descendants of both Western and non-western background. The average difference between ethnic Danes and citizens with a non-western background is around 25 26 percentage points in both the local and national elections. In the lower turnout

10 Political Studies 00(0) Figure 1. The average marginal difference on voter turnout in three elections. The average marginal difference in turnout of the mentioned variables on turnout compared with their relevant reference group, which is non-western ethnicity for ethnicity and primary school for education. For instance, all-else-equal, females vote 2.8 percentage points more than males in local elections in 2013. See Table A2 in Appendix 1 for complete models including standard errors. European election, the corresponding number is 32 percentage points. For the Western group, the differences are smaller, and the turnout gap is, in fact, a bit smaller in the local than in the national elections. Thus, with the Western group, the pattern does not completely follow the law of dispersion. Second, the education gap is striking. Compared to people with a primary school education, the positive average marginal effect of being higher educated is substantial across all educational categories. Furthermore, the average marginal effect of more education on turnout is considerably larger in local elections and in particular in the European elections. For instance, the average marginal difference in turnout between those having completed more than 5 years of higher education and those having completed only elementary school is 16 percentage points in the national election, 22 percentage points in the local election 2013, and 33 percentage points in the European election. It seems that the image of the EU being a project that appeals primarily to the highly educated citizens is a somewhat fair picture. Additional Evidence: Investigating the Law of Dispersion Across Municipalities So far, we have analyzed the law of dispersion by comparing the turnout gap for the same voters in three different types of elections with varying levels of overall turnout. Although the analyses have been consistent with the theory, a potential challenge to the analysis is that it could be differences regarding the types of elections that explain the increasing gap in turnout at the European and local elections compared to the national election. Local elections provide us with an opportunity to investigate whether the size of the turnout gap remains related to the aggregate turnout when the voters are different, but the elections are similar. In Danish local elections, turnout varies substantially between the municipalities, ranging from 61.2% in Copenhagen to more than 80% in some municipalities. While each municipality has its particular political agenda and election dynamics, the local elections are, in general terms, similar for the citizens. No matter where the

Bhatti et al. 11 voters live, they vote for a politician or party to represent them in local politics, and the parties are, for the most part, the same national parties. In Figure 2 (left panel), we plot the difference in turnout between citizens with the lowest level of education and the highest level of education in 95 municipalities in the 2013 local elections. 8 The municipality-specific difference is from a hierarchical Bayesian model with municipality-specific coefficients for education, ethnicity, and gender. 9 The same individual-level control variable as in Figure 1 is included. As the trend line shows, the educational gap in turnout is negatively related to aggregate turnout. In the right panel, we get the same picture when comparing citizens with an ethnic Danish background to citizens with a non-western ethnic background. While the differences implied by the trend lines at a glance might seem small, they are not trivial. For instance, when turnout is 1 percentage point higher, the educational gap is predicted to be 0.4 percentage points lower. Similarly, each 1 percentage point increase in turnout is associated with a 0.3 percentage points drop for the predicted turnout gap between citizens with an ethnic Danish background and a non-western ethnic background. The analysis does not change substantially if we weight by the precision of the municipality differences (see Table A3 in Appendix 1 for regression tables). Overall, the declining turnout gap illustrated in Figure 2 is consistent with the analysis in Figure 1. This finding shows that when we compare different voters over similar elections, we arrive at the same conclusion as when we compare the same voters over different elections: As predicted by the law of dispersion, tower rates of turnout are related to higher differences in turnout between social groups. Conclusion and Discussion We have explored what predicts cumulative turnout and what characterizes those who always and never vote. So far, little empirical attention has been given to cumulative turnout outside the United States, and the existing research often suffers from having access to only few variables and in many cases just self-reported turnout. Using validated turnout and highly reliable register-based background information from a panel of 2.1 million Danish citizens across three elections, we add important empirical knowledge about turnout patterns across elections. Our analyses show that in the Danish high-turnout context, around 51% of the citizens are core voters and around 40% enter and exit the electorate from election to election. The share of core voters is markedly larger than in lower turnout countries such as the United States and Switzerland. However, more than 9% abstain at every election across consecutive elections. This is quite remarkable since voting in this context is a very easy and low-cost act to do, and the norm of voting is extremely strong in Denmark. When citizens do not even manage to vote here, it is quite likely that they also abstain from participating in other forms of political and societal activities (cf. Pattie et al., 2003; Stolle and Hooghe, 2005), although we emphasize that this is a topic for future research, and here, we have not offered empirical support for this proposition. Indeed, one might wonder how they can be mobilized to take part in elections. The abstainers did not vote in any of the three consecutive elections, that is, this group did not engage at all with the social contract of representative democracy. These eligible nonvoters are dominated by relatively many nonnative Danes and many with low levels of education. It is worrisome that almost one-tenth of the electorate simply does not give their support to the core of representative democracy by failing to participate in elections.

12 Political Studies 00(0) Figure 2. Turnout gap at different levels of turnout in the local elections 2013. The left panel shows the relationship between turnout and the difference in turnout between voters with a high education and voters with no education beyond public school. The dots are point estimates of the differences from the Bayesian hierarchical model with 95% credible intervals. The dashed black line shows the relationship when estimated as an ordinary least squares (OLS) regression. The solid gray line shows the relationship from a regression where the points are weighted by their precision. The right panel shows the relationship between turnout and the difference in turnout between voters with a non-western background and an ethnic Danish background.

Bhatti et al. 13 There might be many less troubling reasons to miss a single election, but missing three consecutive elections signifies that a share of the public consistently has no wish to participate. It is not only worth monitoring the size of the group in future elections but also to engage in mobilization efforts to provide the best opportunities for this group of habitual nonvoters to become familiar with democracy. The law of dispersion provides a good framework to understand cumulative turnout and what characterizes core voters, irregular voters, and abstainers. According to Tingsten s (1937) law of dispersion, the general rule is that voting frequencies rise with rising social status and that the differences in turnout are lower, the higher the general turnout is (Lijphart, 1997). Or put differently, the higher the salience of the election, the more equal is the participation across social demographic factors and vice versa. Our findings suggest that rather than irregular voters being a special category of voters, propensity to drop out is a linear function of the salience of the election. In other words, irregular voters can be seen as somewhere between abstainers and core voters. In this sense, the abstainers do not seem to have unique characteristics but are instead voters who on average are more likely to be men, have less education, and are less likely to be ethnic Danes, which suggest that it is possible to mobilize them especially in high salience election. For cumulative participation, we can use the logic of the law to pose the question whether the differences in voter participation for various sociodemographic groups are larger when the number of consecutive elections in which they have participated declines. Looking at the composition of the groups, we learn that a substantial share of the core voters have finished a higher education, have a higher income, and are less likely to have a non-western background. The opposite is the case for the abstainers, where there is a substantial overrepresentation of citizens with a non-western background and with less education. From a model with background variables, we learn that ethnic background and educational attainment are strongly correlated with cumulative participation. Higher educated and ethnic Danes are more likely to participate in multiple elections. Thus, the inequality across sociodemographic groups that single-election studies often find also holds firm for cumulative turnout. In the final part of our analysis, we applied the law of dispersion in a more traditional way and looked at the predictors of turnout in each of the elections to find out whether the difference in turnout between different sociodemographic groups varies across election type. In a context where turnout varies from 56.3% in the European Parliament election over 71.9% in the local elections to 85.9% in the national election, our analysis mostly confirms the law of dispersion but adds some new nuances. Regarding ethnic background, the difference between the group least likely to vote, voters with a non-western background, and the group most likely to vote, ethnic Danes, is largest in the European election but practically equivalent in the local and the national elections. Compared to voters with a Western background, voters with non-western background fall further behind in the national election than in the local elections. For education, the law of dispersion holds firm. This also means that peripheral voters mainly drop out of second-order elections but are more mobilized in first-order elections. The findings are sobering for those who, like Mr Verhofstadt in our introductory quote, care about the representativeness of the voters in the European elections. Education strongly predicts turnout in the European elections, as does ethnicity. Thus, as the law of dispersion would predict, European elections seem to be the least representative of the general population of voters.

14 Political Studies 00(0) Acknowledgements An earlier version of the article has been presented at the European Political Science Association s Annual Meeting 2016, the Danish Political Science Association s Annual Meeting 2016 and at a seminar at the Department of Political Science at the University of Copenhagen. We thank the participants at all three events for useful suggestions. The project has received funding from the Danish Council for Independent Research (grant no. 12-124983) and the Danish Youth Council. The data is stored on servers at Statistics Denmark. Due to security and privacy reasons, the data cannot be made available on the Internet. Funding The author(s) received no financial support for the research, authorship, and/or publication of this article. Notes 1. See Heath (2000) for an exception and new studies (e.g. Bhatti et al., 2016b; Bhatti and Hansen, 2012; Dahlgaard, 2018; Hansen, 2016). 2. In this context, the concept of core and peripheral voters refers to frequency of voting, where core voters refer to the type of citizens who manage to vote no matter the type of election. The terminology was introduced by Campbell (1960) and has also been used by Sigelman and Jewell (1986) and, recently, by Ansolabehere and Schaffner (2016). 3. Empirical investigations of Tingsten s law are rare, but some examples exist. Rosenstone and Hansen (1993) compare average midterm and presidential election turnout between 1952 and 1988 for different subgroups and argue that Tingsten s law of dispersion holds firm in a US context. Similarly, Persson et al. (2013) study the sociodemographic composition of the electorate in a Swedish county in a 2010 election and a reelection in 2011 and conclude that the inequalities in turnout do increase when turnout declines. Finally, Sinnott and Achen (2008) argue that the law of dispersion holds in Europe and United States for most demographic categories, but that Lijphart s (1997) focus on social classes is misguided. 4. The ratio is calculated by dividing turnout at the latest national election by turnout at the European Parliament elections of 2014, based on figures from International IDEA (2016). Missing data from Latvia explains why only 27 countries are included. Unfortunately, similar data for turnout in local elections are not available in a form that enables the same type of calculation. 5. Voters can cast an early vote up to 3 months ahead of the elections by going to a preelection polling place, an option used by 4% 9% of the voters in the three elections (Bhatti et al., 2016b). Citizens cannot use mail-in voting. 6. The data are stored on servers at Statistics Denmark. Due to security and privacy reasons, the data cannot be made available on the Internet. 7. Individuals are classified as native Danes if at least one parent was born in Denmark and holds Danish citizenship, irrespective of whether the individuals were born in Denmark and/or hold Danish citizenship themselves. Individuals who do not meet these criteria are, following Statistics Denmark, considered either immigrants (if they were born outside Denmark) or descendants (if their parents were born outside Denmark). 8. We exclude the three small municipalities of Læsø, Ærø, and Samsø as they each have too few citizens with either a non-western ethnic background or a higher education to conduct the analysis. 9. Some municipalities have few voters in some categories, which mean that if few voters for some arbitrary reason vote/abstain, they could have a great impact on the cross-municipality estimates. When we fit a Bayesian hierarchical with noninformative priors, the municipality-specific effects are sampled from the same overarching distribution. This way, the estimates become a compromise between the strength of the signal of the municipality-specific effects and the precision of the overarching prediction of municipality effects. In other words, the Bayesian model reduces the risk that we make inferences based on outliers from small municipalities with weak signals. ORCID id Kasper M Hansen https://orcid.org/0000-0002-8286-4771 References Ansolabehere S and Schaffner B (2016) Beyond the Core and Periphery: A New Look at Voter Participation across Elections. Working Paper. Presented at SPSA, San Juan, Puerto Rico.

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